Identity-Based Hierarchical Key-Insulated Encryption without Random Oracles
- Y. Watanabe and J. Shikata
- PKC 2016
- LNCS 9614
Key-insulated encryption is one of the effective solutions to a key exposure problem. Recently, identity-based encryption (IBE) has been used as one of fundamental cryptographic primitives in a wide range of various applications, and it is considered that the identity-based key-insulated security has a huge influence on the resulting applications. At Asiacrypt’05, Hanaoka et al. proposed an identity-based hierarchical key-insulated encryption (hierarchical IKE) scheme. Although their scheme is secure in the random oracle model, it has a “hierarchical key-updating structure,” which is attractive functionality that enhances key exposure resistance.